Quartz porphyry is a widely distributed intrusive igneous rock formed from magma in small (relatively speaking, an area of 5000 square kilometres is 'small' in geological terms) intrusive structures, such as dikes and sills, which were usually formed at no great depth. It is generally light coloured, usually grey, pink, red or violet in colour, and contains more than 65 percent silica and more than ten percent quartz, as feldspar, mica and quartz. Research Quartz Porphyry
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Abbreviations
Research Quartz Porphyry
